Vaquita porpoises. As of yesterday there were 12 of them left. They have no natural predators, and live in an area of the gulf of California with plentiful food, and once numbered in their hundreds if not thousands. They get caught in illegal gill nets though, as by catch, of local fishermen. There is no reason for them dying, except that locals are too cheap/too greedy to buy nets that are modified to exclude by catch. They are not evenlanded or eaten by the locals, just their corpses cut loose to decompose in the sea. It is a human made tragedy.